No, Thameslink and Gatwick Express are not the same, although both are operated by the parent company Govia Thameslink Railway (GTR). The Gatwick Express is a dedicated "premium" non-stop service that runs exclusively between Gatwick Airport and London Victoria Station, taking about 30 minutes. In contrast, Thameslink is a regional commuter line that runs through central London, stopping at Gatwick as part of a much longer route. Thameslink trains are often slightly cheaper and connect the airport to stations like London St Pancras International, Farringdon, and London Bridge, making them a better choice if you are heading to the City, the Eurostar, or North London. While the Gatwick Express is faster if your final destination is Victoria, Thameslink provides much more flexibility and a wider range of central London destinations, though the trains can be more crowded during rush hour as they serve regular commuters as well as airport travelers.